The effect of transition metal ions (M2+=Mn2+, Ni2+, Co2+, Cu2+) on the chemical synthesis polyaniline as counter electrodes in dye-sensitized solar cells

The effect of transition metal ions(M~(2+)=Mn~(2+),Ni~(2+),Co~(2+),Cu~(2+)) on the chemical synthesis of polyaniline(PANI) used as a platinum-free counter electrode(CE) in dye-sensitized solar cells(DSSCs) was investigated.PANI was synthesized by co-polymerization of aniline in the presence of different transition metal ions by using potassium dichromate in acidic medium. It was found that the ion doping of PANI showed a certain catalytic activity for the regeneration of traditional iodide/triiodide(I~-/I_3~-) redox couples. The power conversion efficiency(η) of PANI CEs doped with Mn~(2+),Ni~(2+),Co~(2+) (4.41%, 2.36% and 2.10%, respectively) were higher than 1.94%, the value measured for PANI CE without doping. Doping with Cu~(2+)decreased the power conversion efficiency of PANI CE(PANI-Cu~(2+) η = 1.41%). The electrical properties of the PANI, PANI-Ni~(2+), PANI-Co~(2+),PANI-Mn~(2+) and PANI-Cu~(2+) were studied by cyclic voltammetry(CV), impedance(EIS), and Tafel polarization curve. The experimental results confirmed that PANI was affected by the doping of different transition metal ions(M~(2+)=Mn~(2+),Ni~(2+),Co~(2+),Cu~(2+)). These results indicate a potential application of ion doped PANI as counter electrode in cost-effective DSSCs.     

In situ electrodeposition of nickel cobalt selenides on FTO as an efficient counter electrode for dye-sensitized solar cells

Construction of transition metal selenides with high electrocatalytic performance is of significant importance, but it is still a challenge to develop the corresponding counter electrodes (CEs) by an electrodeposition technique. In the present work, nickel cobalt selenide (Ni_xCo_ySe) films are prepared in situ on fluorine-doped tin oxide (FTO) glasses through a potential reversal electrodeposition technique. The morphology and electronic structure of Ni_xCo_ySe films can be tuned by controlling the Ni/Co molar ratio in electroplating solution. Specially, Ni_xCo_ySe-6 film (the Ni/Co molar ratio of 1:1) with the optimized interaction between the Ni and Co elements displays numerous particles composed of sheets attached with nanocrystals, resulting in the more electrocatalytic active sites. Benefiting from the unique morphology and optimized synergistic effect, Ni_xCo_ySe-6 CE exhibits superior electrocatalytic activity for the triiodide reduction. Then, the dye-sensitized solar cell (DSC) fabricated by Ni_xCo_ySe-6 CE has demonstrated a power conversion efficiency (PCE) over 7.40%, which is higher than that of platinum (Pt)-based device (6.32%). Furthermore, Ni_xCo_ySe-6 array CE is also prepared by using polystyrene array as template. The PCE of the DSC with Ni_xCo_ySe-6 array CE reaches its maximum value of 7.64% and 20.9% larger than that of Pt-based device.     

Process intensification in small scale extraction columns for counter-current operations

This article describes a study to investigate the intensified liquid–liquid extraction by a novel, millistructured, stirred-pulsed column. The column has an inner diameter of 15 mm and is modularly designed with sections of 220 mm height consisting of 10 stirred cells. Experimental investigations were carried out in a column with five sections. The stirred cells enable high energy input, and therefore high specific surface and good extraction efficiencies. The backflow was minimized with narrow plates between the cells. Hence, the dispersed phase coalesces at the plates that separate the stirred cells. The coalescence area is destroyed by continuous pulsation of the fluid column, which transports the dispersed phase into the next stirred cell. The hydrodynamic and mass transfer inside the column was characterized with the EFCE – test system water (continuous)/acetone/n-butylacetate (dispersed). We achieved a dispersed phase hold up inside the active extraction part up to 50%, and a specific surface of over 3000 m²/m³. The extraction efficiency was measured to 17 and 25 stages per meter for the mass transfer direction (d → c) and (c → d), respectively. The comparison with other conventional pilot plant columns shows high extraction efficiency, but also a loss in total throughput.     

Enhanced performance of counter flow SOFC with partial internal reformation

We study a counter-flow solid oxide fuel cell system and consider the challenges faced in minimizing thermal variations from the nominal operating conditions for a reasonable range of power tracking. Blower dynamics, reformer transport delays, spatial distribution of the heat generated and the resulting thermal response are among the issues considered. A novel approach, relying on partial internal reformation of the feedstock is proposed as a remedy to maintain a strong level of power tracking with minimal thermal stress to the fuel cell.     

用TTL 计数器和译码器组成数传MODEM

根据定时式脉冲鉴频原理,本文给出一种适用于计算机无线电通信的调制解调器,该电路用TTL计数器和译码器产生定时信号,实现频移键控调制和解调,其数据传送速率为1200bps。     

DCS中顺序控制功能块应用及综合设计

在集散控制系统中,控制功能的实现是依靠控制功能块正确使用和控制回路图的正确连接。文中分析研究了常用的顺序控制功能块即定时器和计数器。对连续控制中选择开关SW-33与顺序控制的综合应用进行了设计分析。编写了顺序控制表。并对集散控制系统中应用实例进行了控制方案实现和运算块程序设计。     

预警机红外对抗技术分析及其对抗措施

基于预警机红外对抗的特点和战术运用,建立了预警机红外干扰弹对抗红外制导导弹的数学模型,对其干扰效果作了初步分析,并提出了一些针对预警机红外弹的对抗措施.     

作战飞机对雷达的无源对抗及其仿真建模

无源干扰在高科技战争中发挥着重要作用。针对无源干扰物的运动特性及频率特性进行仿真建模 ,并将其用于我军防空兵的模拟训练有着重要意义。该文介绍了几种无源干扰方式 ,并对箔条干扰建模 ,用于一个基于分布交互仿真技术的模拟训练系统。     

基于单片微机控制的等精度频率计设计制作

介绍了基于单片微机控制的等精度频率计系统的硬件、软件的设计制作.